Lubricating compositions containing phosphorus compounds for lubrication of silver bearings



LUBRICATING COMPOSITIONS CONTAINING PHOSPHORUS COMPOUNDS FOR LUBRICA-TION OF SILVER BEARINGS Richard G. Cunningham, Edwardsville, andTheodore W. Havely and James R. Price, Alton, Ill., assignors to ShellOil Company, New York, N.Y., a corporation of Delaware No Drawing. FiledFeb. 17,1956, Ser. No. 566,106

5 Claims. (Cl. 25233.4)

This invention relates to new and improved lubricating compositions.More particularly, it relates to highly detergent mineral oillubricating compositions which are non-corrosive and wear-resistant tometals, such as silver and alloys of silver and the'like. i

It has been observed that one of the best additive combinations forimparting detergency to lubricants is the combination of a particularclass of oil-soluble metal sulfonates and oil-soluble metal phenates.The supplemental use of conventional anti-oxidants friction reducers andcorrosionand Wear-inhibitors, such as nitrogenand sulfur-containingcompounds, such as thiocarbamates or organic thiophosphates (e.g. zincor calcium dialkyl dithiophosphates and the like), although effective ininhibiting oxidation, corrosion and/ or wear of conventional metalsurfaces, such as steel, steel alloys, babbitt surfaces, cadmium and thelike, have been found to be ineffective for oils which contact silvermetal bearing surfaces, such as are used in certain railroad dieselengines, for instance the silver wrist pin bushings, or in aircraftengines which have silver bearing surfaces.

It has now been discovered that these detergent lubricants containingthis particular oil-soluble sulfonate phenate additive combination canbe rendered non-corrosive and wear resistant toward silver surfaces whensupplemented with minor amounts of a particular class phenates reducesthe coeflicient of friction of the com-' position making them betterlubricants, particularly when employed in the lubrication of contactingsilver-steel surfaces.

The sulfonates are oil-soluble neutral and/or basic polyvalent metalpetroleum sulfonates, of which petroleum sulfonates of the metals ofgroup H of the periodic table having an atomic number of from 12 to 56,inclusive, are preferred, and especially of the alkaline earth metals.Suitable sulfonates include the neutral and/or basic calcium, barium andmagnesium petroleum sulfonates of oil-soluble petroleum sulfonic acids.The acids can range in molecular weight from about 350 to 550 andpreferably are in the range of from 400 to 500. By basic petroleumsulfonates is meant that the amount of neutralizing agent, such ascalcium carbonate and/or calcium hydroxide, which is used to neutralizethe petroleum sulfonic acid, is in excess of that which is normallyrequired to neutralize the acid. The excess should be from to 100 andpreferably between 20 to 60 percent that normally required to neutralizethe acid.

The phenates used in compositions of this invention are oil-solubleneutral and/or basic polyvalent metal polyphenates. By polyphenates ismeant to include a plurality of phenolic radicals linked togetherthrough a carbon, such as where a plurality of simple phenates arecondensed at positions ortho and/ or para to the phenolic hydroxy groupthrough alkylidene (methylene) radicals. The cationic portion of thephenate can be the same as chloride.

that in the sulfonate and usually will be, but different i cations maybe used. The alkaline earth metal salts of.

the condensation product of an alkylphenol (e.g. p-octylphenol) withformaldehyde, acetaldehyde or benzaldehyde, e.g. calcium or barium saltsof octylphenol-form ing a P-C linkage and the halogen may be (I)directlyor (II) indirectly connected to the phosphorus atom in themolecule.

Compounds of group I are characterized by the follow ing structure:

RP=S

- wherein R is an aromatic radical directly bonded to phosphorus, X is ahalogen and preferably a middle halo-' gen, such as chlorineand/orbromine. Compounds of this class can be prepared by the methodsdescribed by G. M. Kosolapofi in *Organo Phosphorus Compounds,- JohnWiley and Sons or by any other suitable means.

An illustrative substance, phenyl phosphorus thiodichloride, can beprepared by reacting, in a suitable reaction vessel, 0.3 mole ofbenzene, 0.9 mole of phos-- phorus trichloride and 0.3 mole of anhydrousaluminum The mixture is then cooled to about 30 C. and 0.31 mole offlowers of sulfur is added while stirring. The reaction is exothermicincreasing the temperature to about 60 C. After the temperature beginsto de-- crease, the mixture is heated briefly to about C. Excessphosphorus trichloride is distilled off at reduced pressure and theremainder poured into ice. The resulting mixture is extracted withnaphtha, the solvent extracts combined, washed with water and filtered.The naphtha is removed by distillation, leaving behind the desired 'endproduct phenyl phosphorus thiodichloride, C H PSCl Other suitablecompounds include, butylphenyl phosphorus thiodichloride, octylphenylphosphorus thiodichloride, butoxyphenyl phosphorus thiodichloride,naphthyl phosphorus thiodichloride, phenyl phosphorus thiodibromide andmixtures thereof. I

"The phosphorus compounds of group H are essentially halo-containingesters of alkenephosphonic acids, which compounds can be represented bythe formula:

(RO)r-PR wherein R' is an alkene radical directly bonded to phosphorus,preferably a vinyl radical, R" is a halogen-cone taining hydrocarbylradical, such as haloalkylor haloaryl radicals. Compounds of this typecan be prepared by the emthod described by M. I. Kabachnick et al.,Bull. Acad. Sci. USSR Classe Sci. Chem, 1947, pages 233-34. Examples ofsuch compounds include bis(betachloroethyl)vinyl phosphonate,bis(beta-bromoethyl)vinyl phosphonate, bis(chlorophenyl)vinylphosphonate, bis- (chlorocyclohexyl)vinyl phosphonate and mixturesthereof.

The addition of minor amounts of arylamines to compositions of thisinvention may at ti'me be beneficial. Such arylamines preferably have atleast two aromatic rings. Preferred compounds are, for example, thenaphthylamines: primary, secondary or tertiary alkyl, aryl aralkylradicals are attached directly to a nuclear carbon atom of the aromaticnucleus or preferbly to the nitro- Patented Nov. 22, 1960.

gen atom, such as phenyl-alphaor phenyl-beta-naphthylamine, tetralinnaphthylamine, aJpha,alpha-, a lpha,beta-, orbeta-beta-dinaphthylamines, various phenanthryl-,anthry1-naphthylamines, .xenyl naphthylamines benzyl phenylnaphthylamines, diphenyl naphthylamines, phenyl xenyl naphthylamines,dixenyl naphthylamines; also vanous phenanthryl, anthryl or picyl phenylamines, etc. The N-aryl substituted naphthylamines are in general moreuseful for the present purpose. 1

The base for additives of this invention can be any natural or syntheticoil material having lubricating properties. Thus, the base may be ahydrocarbon oil obtained from a paratfinic, naphthenic, asphaltic sto'ckand/or mixtures thereof. The viscosity of these oils may vary over awide range, such as from 45 SUS at 100 F. to 100 SUS at 210 F. Thehydrocarbon oils may be blended with fixed oils, such as castor oil,lard oil and the like and/or with synthetic lubricants, such aspolytmerized olefins, copolymers of alkylene glycols and alkyleneoxides, organic esters, e.g., di-2-ethylhexyl sebacate, dioctylphthalate, trioctyl phosphate; polymeric tetrahydrofuran, polyalkylsilicones, e.g., dimethyl silicone and the like. If desired, thesynthetic lubricants may be used as the sole base lubricant or admixedwith fixed oils and derivatives thereof.

The general formulations of compositions of this invention may berepresented by:

The following compositions are illustrative of preferred compositions ofthe invention:

Composition A Oil-soluble Ca petroleum sulfonate percent S.A. 2.3Oil-soluble Ca salt of octylphenol-formaldehyde condensation product(av.-mol. wt. 1000) percent'S.A 2.3 Phenyl phosphorus thiodichloridepercent P 0.1 Mineral lubricating oil (SAE 40) Balance Composition BOil-soluble Ca petroleum sulfonate "percent S.A. 2.3 Oil-soluble Ca saltof octylphenol-formaldehyde condensation product (av.-mol. Wt. 1000)percent S.A 2.3 Bis(beta-chloroethyl)vinyl phosphonate percent P 0.1Mineral lubricating oil (SAE 40) Balance Com position C Oil-soluble Capetroleum sulfonate .percent S.A. 2.3 Oil-soluble Ca salt ofoctylphenol-formaldehyde condensation product (av.-mol. wt. 1000)percent S.A 2.3

Phenyl phosphorus thiodichloride .percent P 0.1

Phenyl-a-naphthylamine --percent wt 0.4

Mineral lubricating oil (SAE 40) Balance Composition D Gil-soluble Capetroleum sulfonate "percent S.A. 2.3 Oil-soluble Ca salt ofoctylphenol-formaldehyde condensation product (av.-mol. wt 1000) percentS.A 2.3

Phenyl-n-naphthylamine percent wt..- 0.4 Bis(bcta-ch1oroethyl)vinylphosphonate percent P-.. 0.1 Mineral lubricating oil (SAE40) Balance 1S.A.= sulfate ash.

tion product (av.-mol. v/t. 1000); and from about 0.1

to about 0.5% P of phenyl phosphorus thiodichloride, butylphcnylphosphorus thiodichloride, phenyl phosphorus thiodibromide,bis(beta-chloroethyl)vinyl phosphonate, bis(betabromoethyl)vinylphosphonate, bis(chlorophenyl)viny1 phosphonate and mixtures thereof.

The beneficial properties which compositions of this invention have whenused to lubricate silver surfaces is demonstrated by the data in Table Iwhich were obtained by subjecting test compositions to a modifiedfour-ball machine similar in principle to the Boerlage apparatusdescribed in Engineering, vol. 136, July 13, 1933, using a rotatingsteel top ball and 3 silver discs, operated at 700 r.p.m. spindle speed,22.8 Kg load and 300 F. 011 temperature.

TABLE 1 Ca Salt 0! 4-132111 Test Results Ca Petro- Oetylphcnol- Phos-Composlleum Sul- Formaldephorus tion ionate hyde Con- Com- 4 densationpounds 1 f d, m r

Product A 2.3% 2.3% S.A l 0. 015 1.39 0. 64 18.. 2.3% 2.3% S.A 2 0.014 1. 67 1.21 C 4 2.3% 2.3% S. 1 0. 0000 1. 40 D 2.3% 2.3% S. 2 0. 0105l. 83 E 2.3% 2.3% S.A 3 0.023 2.14 1.12 F 2.3% 2.3% S.A 4 0. 031 1. 595. l6 (3.... 2.3% 2.3% S A.. 5 0. 036 2. 29 1. 41 H- 2.3% 2.3% 8.11....6 0.07 1.81 2. 40 I. 2.3% 2.3% S.A 7 0. 000 2. 94 0. 83 1.. 2.3% 2.3%S.A.-.. 8 0.072 2.81 9. 03 K. 2.3% 2.3% 8.6. 9 0. 091 2. 15.7 L 2.3%2.3% S.A- 10 0. l8 3. 63 14. 4 M- 2.3% 2.3% S. 11 0. 046 4. 0 1.41 N-2.3% 2.3% S. 12 0.123 4. 5 2. 43 0..-. 2.3% 2.3% S 0.051 2. 40 3.44 P2.3% 0. 050 2.11 Q" 0. 052 2.71 2.3% 0.051 2. 40 2.3% 0.039 1.38 0.047 1. 51

1 In Compositions A through T the oil used was a refined SAE 40 mincmllubricating oil, of which compositions A, B, C, and D are illustrativeof the present invention, while compositions E through T are used forcomparison.

5 All phosphorus compounds tested in compositions A through '1 were usedin amounts of 0.1% P and they were as follows: I

1. phenyl phosphorus thiodichloride (present invention)bis(beta-chloroethyl) vinyl phosphonate (present invention) diethylchloro phosphate phenyl phosphorus dichloride 0.0-diethylchlorothiophosphatc phenyl phosphorus oxydichloride dibutyl chlorophosphate dioctyl phosphitc trimethyl phosphitc 10. tris(2-chloroethyl)phosphite l1. triethyl phosphorotrithioite 12. tripropylphosphorotrithioite 3 Average three determinations: f=coeiiicient offriction; d=sear diameter in mm.; r=ratio of friction coeifieient of theCa salt blend to that of the base oil, both containing a phosphoruscompound at 0.1% l.

4 1(liompositions C and D also contained 0.4% wt. of phenyl-mnaphthylame.

From the above data it is apparent that substituting otherphosphoruscompounds (compounds 3-12) for the phosphorus-halogencompounds of group I or 11 (compounds 1 and 2) as used in compositionsofthis invention or removing either of the two essential salts used incompositions of this invention, results in inferior compositions Whichare unsuited for use of lubricating silver surfaces.

In addition to the additives already described lubri eating oilcompositions contemplated herein may contain other agents, such aspour-point depressants, oiliness agents, blooming agents, compounds forenhancing the viscosity index of the lubricating oil, peptizing agents,etc.

We claim as our invention:

1. A lubricating oil composition consisting essentially of a majorproportion of a mineral lubricating oil from about 0.01% to about 15% ofan oil-soluble alkaline earth metal petroleum sulfonate and from about0.05% to about 15% of an oil-soluble alkaline earth metal salt of analkylphenol-aldehyde condensation product, which composition causescorrosion and wear of silver and silver alloys and which is renderednon-corrosive and wear-resistant thereto by addition of from about 0.01%to about 5% of a pentavalent phosphorus chlorine containing compoundhaving a P-C linkage selected from the group consisting of phenylphosphorus thiodichloride and bis(beta-chloroethyl)vinyl phosphonate.

2. A lubricating composition which is non-corrosive and wear-resistanttoward silver consisting essentially of a major proportion of minerallubricating oil containing from 0.01% to 15% of oil-soluble calciumpetroleum sulfonate, from 0.05% to 15% of oil-soluble calcium salt ofoctylphenol-formaldehyde condensation product, and from 0.01% to 5% ofphenyl phosphorus thiodichloride.

3. A lubricating composition which is non-corrosive and wear-resistanttoward silver consisting essentially of a major proportion of minerallubricating oil containing from 0.05% to 15% of oil-soluble calciumpetroleum sulfonate, from 0.01% to 15% of oil-soluble calcium salt ofoctylphenol-formaldehyde condensation product, and from 0.01% to 5% ofbis(beta-chloroethy1)vinyl phosphonate.

4. A lubricating composition which is non-corrosive and wear-resistanttoward silver consisting essentially of a major proportion of minerallubricating oil containing from 0.05% to 5% of oil-soluble calciumpetroleum sulfonate, from 0.1% to 6% of oil-soluble calcium salt ofoctylphenol-formaldehyde condensation product, and from 0.05% to 2% ofphenyl phosphorus thiodichloride.

5. A lubricating composition which is non-corrosive and wear-resistanttoward silver consisting essentially of a major proportion of minerallubricating oil containing from 0.05 to 5% of oil-soluble calciumpetroleum sulfonate, from 0.1% to 6% of oil-soluble calcium salt ofoctylphenol-formaldehyde condensation product, and from 0.05% to 2% ofbis(beta-chloroethyl)vinyl phosphonate.

References Cited in the file of this patent UNITED STATES PATENTS2,223,793 Peery Dec. 3, 1940 2,260,304 Engelize Oct. 28, 1941 2,614,990Harman et al. Oct. 21, 1952 2,629,693 Barton et al. Feb. 24, 19532,708,204 Bell et al. May 10, 1955 2,736,701 Nefl Feb. 28, 19562,767,142 Morris et a1. Oct. 16, 1956 2,824,839 Templeman Feb. 25, 1958FOREIGN PATENTS 151,096 Australia Apr. 27, 1953

1. A LUBRICATING OIL COMPOSITION CONSISTING ESENTIALLY OF A MAJORPROPORTION OF A MINERAL LUBRICATING OIL FROM ABOUT 0.01% TO ABOUT 15% OFAN OIL-SULUBLE ALKALINE EARTH PETROLEUM SULFONATE AND FROM ABOUT 0.05%TO ABOUT 15% OF AN OIL-SOLUBLE ALKALINE EARTH METAL SALT OF ANALKYLPHENOL-ALDEHYDE CONDENSATION PRODUCT, WHICH COMPOSITION CAUSESCORROSION AND WEAR OF SILVER AND SILVER ALLOYS AND WHICH IS RENDEREDNON-CORROSIVE AND WEAR-RESISTANT THERETO BY ADDITION OF FROM ABOUT 0.01%TO ABOUT 5% OF A PENTAVALENT PHOSPHORUS CHLORENE CONTAINING COMPOUNDHAVING A P-C LINKAGE SELECTED FROM THE GROUP CONSISTING OF PHENYLPHOSPHORUS THIODICHLORIDE AND BIS(BETA-CHLORETHYL)VINYL PHOSPHONATE.